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Comment Re:Nope. Typo. (Score 1) 622

That time was still steeped in an oral tradition, and much was still not written down. For instance, in the Christian Testament only Mark was written contemporaneously with Jesus. The other books were written well after his death, using sources that have always been suspect.

Mark also was written decades after Jesus death - though at a time when people still lived who remembered him.

Not sure what you mean by "suspect". We have excellent evidence the other Gospel's were written using sources that we no longer have - but what makes them "suspect"?

Comment Re: Old testament (Score 4, Informative) 622

Dead Sea Scrolls. Ever heard of them? They include a fair chunk of the Tanakh ("Old Testament" to Christians) written down as much as 400 BCE (before the birth of Jesus). The Ketef Hinnom silver scroll from Jerusalem dates from 600 BCE, and is clearly part of a long established written tradition. The Israelites/Jews were writing down their religious history for a thousand years before the Christians (we have religious inscriptions in Hebrew that are that old).

Comment Re: Priorities (Score 1) 71

A wall has a permanence to it that spans across Administrations.

Ever notice, say, a car repair shop where they have an 8 foot wall topped by razor wire? They build those because it reduces theft. Walls work, otherwise they wouldn't be built so often by property owners (both private and public).

Because no one along a 3145 km border would ever dig under the fence/wall, or cut a hole through it?

Belief in the effectiveness of a border barrier in stopping border crossers depends on never having looked at the problem in any depth. Pointing to the effectiveness of the East German border barrier as 'proof' of effectiveness simply highlights the ignorance of the advocates.

Here are some issues with this scheme.

The East German border was only 40% of this length, but required 47,000 border guards (there are only 20,000 border patrol agents), and it still depended on its effectiveness on a "shoot to kill on sight" policy, the use of land mines, and automatic firing weapons. Without the automatic use of deadly force the border would have remained quite leaky. U.S. law does not permit the use of death-traps or assassination by law enforcement.

Any such border barrier is only as strong as its most vulnerable point. Border crossers, and the coyotes who make money off of them, will be scouting the entire length looking for the spots where circumvention is easiest, and channel the traffic flow through that point, shifting to other points as needed as resources are thrown into the breech to close it. This is similar to U.S. efforts to block drug smuggling, which has never been effective since new holes are opened faster than old ones are closed - cocaine prices are currently at historic lows.

A substantial stretch of the US-Mexico border is through extremely rugged, remote terrain (which is why the border runs there) where it would be extremely difficult to build a fence or to patrol one. This extremely rugged terrain however is not impenetrable to motivated border crossers however, the rugged terrain provides cover in fact. No part of the East German border was as remote and rugged as this.

The desire by right-wingers to emulate the practices of Communist states is puzzling.

Comment Re:The Fictional Radioactive Materials (Score 1) 242

...You can't make any money on it. But Boeing is taking out patents. So, the only conclusion is that Boeing has stumbled onto an idea that will make fusion engines a practical reality before the patent runs out.

Here's another conclusion - Boeing has decided that the publicity for this patent is worth the cost of filing it. Or that the corporate inventor and patent attorneys find that this is a good way to keep their jobs funded (not exclusive with the previous possibility). Somehow these seem far more likely than a secret new technology nobody else has dreamed of (and is not evident in the actual patent).

Comment Re: WHAT radioactive materials? (Score 1) 242

Laser initiated fusion works just fine. It's just not net energy positive. But you don't need it to be when you're just using it as a neutron source. The fission reaction it kicks off is enthusiastically energy positive.

For some extremely unusual definitions of "fine" perhaps. At least it exists, which may be the very low bar you are setting for "fine".

This paper reports on the current state of the art of laser initiated fusion. The accomplishment was to get slightly more energy (about 14 kJ) out the D-T fuel (~30% more) that was deposited in the fuel itself. This was less than 1/10 the laser beam energy delivered to the capsule though (150 kJ).

Although fission, produced by a fusion neutron, produces more energy than the fusion reaction itself, the ratio is about 17-fold, which just barely compensates for the current low yield relative to the laser pulse. Meanwhile the best available lasers for this type (ultra-short tailored pulses) are 0.5% efficient, and the ability to convert fission heat into electricity to drive the laser in the aircraft would be on the order of 10%, and then we need this system to perform at much larger than system break-even levels to drive an actual aircraft. Fusion energy schemes typically assume a yield advantage larger than 10-1 (usually 100-1) to make the system a viable energy producer. So we are short by a factor of 100,000 or so in terms of system capability (fusion explosion round trip back to laser pulse generation) to support the concept. There are plans to upgrade the laser using diode pumps, which should improve its efficiency by a factor of 6, which helps, but that hardly puts a major dent in the short fall.

Oh, and the laser currently is as large as a sports stadium, and can only fire a few shots a day, instead of hundreds per second (a 1,000,000-1 repetition rate shortfall) and the fusion target is made out of gold and costs $10,000 per shot (the amortized cost per shot given the cost of the whole facility to do it is on the order of a million dollars). Factoring in the enormous decrease in target costs (factor of 100,000 say) and size of the laser (lets say a factor of 10,000 to fly it), we are looking at a figure-of-merit short fall of something like 20 orders of magnitude to turn the concept into reality. But other than that laser fusion works just fine.

Comment Re:Big giant scam ... (Score 1) 843

Surprisingly enough, the production line is not gone, though it is shut down. The decision to shutdown production was coupled with a deliberate decision to preserve the F-22 production capability for possible reactivation. The estimated cost for reactivation of the mothballed line is on the order of 200 million dollars, the cost of one or two aircraft.

If you think it really can be restarted for $200 million (this is the US Military Industrial Complex we're talking about), then I've got a bridge to sell.

If we have 1 to 2 years warning, sure, we might be able to do that...

What happens if we have 6 weeks warning?

Well the fly-away cost for two F-22s is $300 million, so I was already providing for some cost growth. And, sure, I would not be surprised if it was more - nonetheless that is the quoted estimate.

Even 1-2 years is not enough lead-time. The lead-time from order to delivery when the line was running was 3 years. Add to that the reactivation time (perhaps that could be collapsed into the normal lead time though as the full line wanted be needed initially). And the production rate was 24 a year. So to double the fleet would take at least a decade.

It would not be the response to a sudden emergency, but to a longer term assessment of the strategic situation.

Comment Re:Big giant scam ... (Score 1) 843

Sure, but we didn't buy enough F-22s.

The production line is gone, shut down, history... If we have to fight someone who can actually fight back, such as Russia or China, those F-22s will simply be too few to do much.

How many would have been the "right" number? One of the principle reasons that production was curtailed was that projected threats from Russian and China did not materialize.

Surprisingly enough, the production line is not gone, though it is shut down. The decision to shutdown production was coupled with a deliberate decision to preserve the F-22 production capability for possible reactivation. The estimated cost for reactivation of the mothballed line is on the order of 200 million dollars, the cost of one or two aircraft. So if a real need for the F-22 were to appear then it would be possible to put it back into production. This is really the best of both worlds: we avoid sinking tens of billions into likely unneeded excess inventory, while still having the capability to produce more if a demonstrated need arises.


Comment Re:"as a means to raise awareness ..." (Score 1) 76

Depends on what the term "killer asteroid" means. For a once-in-five-hundred-thousand-year civilization destroying asteroids larger than 1 km we have already identified all of them. Possible threats from this population can be projected developing centuries in the future.

For the less extreme threats in the ranges from 100 meters to 1000 meters (which covers impacts in an energy range from 100 megatons to 100,000 megatons) we do have a good way to go, but we are closing in on a 90% detection rate for the larger members of this group.

A 100 meter, 100 megaton asteroid can destroy a city, if it hits it, but is only a localized threat. The large majority of such impactors will cause little or no loss of life since only about 1% of Earth's surface is urbanized. Unless the target is a city the most practical means of dealing with the threat will be local evacuations. For this size a month's warning should be sufficient to deal with the situation. This size can also be completely destroyed by a nuclear explosion, so that a ready-for-launch strategic-sized nuclear warhead could be employed.

A significant fraction of severe threats can never be handled by an Earth-surface survey program - the threat posed by long period comets. This represents as much as 20% of the total threat, but these can only be detected effectively by space-based infrared telescopes, and the warning we will get will only be a couple of years in advance as they approach from the outer reaches of the solar system.

Comment Re:quotation marks (Score 1) 424

The solution, then, is to understand how Google treats punctuation within even a quoted string and modify your search accordingly.

That solution would be a much better solution if the rules for how Google treats punctuation were explicit, easily discoverable and consistent.

If you can point me to a page of documentation revealing these rules, I will appreciate it. Googling for it (assuming it exists) has so far been unsuccessful.

In fact the bit about "consistent" we know is not true, since Google tells us it isn't:

  • "Except for the examples below, Google Search usually ignores punctuation" (usually means unspecified exceptions),
  • and
  • "Even though you can use the punctuation marks below when you search, including them doesn’t always improve the results. If we don't think the punctuation will give you better results, you'll see suggested results for that search without punctuation."
  • (We will ignore what you type whenever we think we know better than you.)

Comment Re:quotation marks (Score 3, Interesting) 424

I agree with AC. The comments by grimmjeeper and Spazmania here are bizarre.

The fact that "." has been used a wildcard in Kleene grammars, and used in regular expressions, is irrelevant.

There is nothing in Google's query instructions that suggests that search strings in quote are regular expressions, or is a Kleene grammar of any sort, or that a period is even a wildcard. It explicitly states that the asterisk is a wild card, no mention of a period.

Comment Re:two schools of thought rear their ugly heads (Score 1) 272

Deflection:possibly, but into what or where?

Easy: away from Earth. It is only the fact that at one point in its multi-billion year orbital history that it happens to come within 4000 miles of the Earth's center of mass that we care about. If we make it miss, by even a small distance, it will continue (typically) for billions of years more.

Asteroid deflections is really just a process of cosmic sheepherding - keeping the orbits of the big rocks from becoming (and remaining) Earth intercepting ones.

Comment Re:Way Premature - And Probably Unnecessary (Score 1) 272

Actually I should have simply said that only "one system be kept ready", not that only one should be built. So make it two, even three for back-up. Well established launch systems have reliability rates of 95%, so high levels of redundancy are not really called for. Still not 10-20. And it still only is needed for one corner case of relatively small threat magnitude. More serious threat call for special missions and have threat timelines long enough to organize them.

Actually testing the interception system was stipulated, but having tested it, you know how to build more.

What this country needs is a good five cent ANYTHING!